1. Field of the Invention
The invention relates to the field of cellular transplantation in living organisms.
2. Description of the Prior Art
Transplantation of somatic cells to supply the function of a deficient organ has been studied for decades. This technology, however, has only been successfully performed for bone marrow in clinical practice. Recent studies in skeletal muscles for Duchenne muscular dystrophy, in the liver for a bridge to transplantation, in the pancreas for islets of Langerhans or in the brain have also shown some inconsistent results.
Cell transplantation in the heart, also called cellular cardiomyoplasty, was most intensely studied, since it may be become a useful tool for repairing injured heart tissue. Like skeletal muscle, transplantation of contractile cells is required for improving the function of the injured heart. Like brain cells, adult cardiac myocytes are terminally differentiated. Most strategies used to attempt to overcome this disadvantage involves transplanting cells which have the ability to multiply. Among all kinds of cells, cultured fetal cardiomyocytes, allogeneic fetal skeletal myoblasts, especially, cultured autologous myoblasts have been shown to have some functional benefits, such as decreased infarct size and increased ejection fraction by 20%-30%. However, the results are again inconsistent. Most recently, several human trials have been initiated in Europe and the first case has been performed in U.S.
The major problem addressed by this technique is that the arrangement of transplanted cells usually is disorganized. These transplanted cells are not able to align with the surrounding cells and are rarely shown to be histologically confluent with recipients' myocytes. Electrical and mechanical non-synchronization between transplanted cells and recipient's tissue remains the major limitation for efficacy in clinical application.